Spark plug
US9948067B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 2017 |
| Grant date | Apr 17, 2018 |
| Priority date | — |
| Expiry date | Sep 5, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug for an internal combustion engine includes a cylindrical metal shell, a center electrode, and a ground electrode. The center electrode has an end portion which protrudes outside an end of the metal shell. The ground electrode is joined at an end thereof to the metal shell and has an inner surface facing the end portion of the center electrode. The ground electrode has a maximum width W meeting a relation of 1.3≤W≤2.0. A distance d between the center of an end surface of the center electrode and the inner surface of the ground electrode on a plane extending through the center of the center electrode perpendicular to an axis of the spark plug is selected to meet a relation of W+0.525≤d≤1.07W+0.66. This ensures the stability of ignitability of the spark plug.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.